気軽
きがる · kigaru · JLPT N1 · na-adj
lighthearted
🎈 気 (mind/spirit) + 軽 (light in weight) = a light mind, so cheerful and carefree
軽 means light in weight, and 気 means mind or spirit. A spirit with nothing weighing on it feels buoyant and easygoing. This is why 気軽に also means casually, without fuss.